javascript - Knex.JS Auto Update Trigger -

i using knex.js migration tools. however, when creating table, i'd have column named updated_at automatically updated when record updated in database.

for example, here table:

knex.schema.createtable('table_name', function(table) {     table.increments();     table.string('name');     table.timestamp("created_at").defaultto(knex.fn.now());     table.timestamp("updated_at").defaultto(knex.fn.now());     table.timestamp("deleted_at"); }) 

the created_at , updated_at column defaults time record created, fine. but, when record updated, i'd updated_at column show new time updated @ automatically.

i'd prefer not write in raw postgres.

thanks!

you can create knex migration using timestamps:

exports.up = (knex, promise) => {   return promise.all([     knex.schema.createtable('table_name', (table) => {       table.increments();       table.string('name');       table.timestamps(false, true);       table.timestamp('deleted_at').defaultto(knex.fn.now());     })   ]); };  exports.down = (knex, promise) => {   return promise.all([     knex.schema.droptableifexists('table_name')   ]); }; 

with timestamps database schema created adds created_at , updated_at column, each containing initial timestamp.

to keep updated_at column current, you'll need knex.raw:

table.timestamp('updated_at').defaultto(knex.raw('current_timestamp on update current_timestamp')); 

to skip knex.raw solution, suggest using high level orm objection.js. objection.js implement own basemodel updates updated_at column:

something.js

const basemodel = require('./basemodel');  class extends basemodel {   constructor() {     super();   }    static tablename() {     return 'table_name';   } }  module.exports = something; 

basemodel

const knexfile = require('../../knexfile'); const knex = require('knex')(knexfile.development); const model = require('objection').model;  class basemodel extends model {   $beforeupdate() {     this.updated_at = knex.fn.now();   } }  module.exports = basemodel; 

source: http://vincit.github.io/objection.js/#timestamps